Technical Field
This invention relates to metal and chemical recycling, and more particularly to an automated system for rendering air bag inflators and other low level detonatable devices inert for recycling.
Background Information
Air bag units for automobiles are widely used throughout the world. They are installed to protect passengers during a crash. Generally, an air bag unit comprises an air bag and an inflator therefor. Upon impact the inflator is actuated and releases gas to rapidly expand the air bag. The inflated air bag forms a cushion between the passenger and, for example, the steering wheel to prevent the passenger from impacting against the steering wheel as the automobile rapidly decelerates.
The inflator has a metallic housing. A gas generant, e.g., in the form of a chemical explosive propellant, is disposed in the housing along with an ignition means for igniting the propellant. The ignition means may be actuated by mechanical shock or by electrical signals generated by suitable sensors.
Typically the housing for an air bag inflator is made of, for example, carbon steel, aluminum alloy and stainless steel. The propellant may have primary components such as NH4NO3 (ammonium nitrate).
When automobiles are scrapped, they are usually compressed. If an automobile is compressed with an unused air bag unit therein, there is the risk that the air bag unit will explode. In order to avoid this risk, the scrapping process is carried out only after actuation of the air bag inflator. The following disposal instructions may be provided to effect actuation:                1. For electric air bag inflators a prescribed current is applied by wires leading from a battery to actuate the inflator. This may be accomplished either with the device in the car or may be accomplished by removing, for example, the steering wheel from the car.        2. For mechanical air bag inflators the inflator is removed from the car, placed within scrapped or used tires and then mechanically actuated.        
While conventional approaches may be suitable for processing small numbers of air bag inflators, a need exists for an automated system and method for efficiently rendering large quantities of air bag inflators and other low level detonatable devices inert for recycling, such as to provide manufacturers and automotive scrapping operations with the option of shipping undeployed inflators to a third party for safe destruction and recycling.